U.S. patent application number 14/115666 was filed with the patent office on 2014-03-06 for method and device for selecting a channel according to a device's mobility.
This patent application is currently assigned to LG Electronics Inc.. The applicant listed for this patent is Bonghoe Kim, Jaewon Lim. Invention is credited to Bonghoe Kim, Jaewon Lim.
Application Number | 20140064252 14/115666 |
Document ID | / |
Family ID | 47139763 |
Filed Date | 2014-03-06 |
United States Patent
Application |
20140064252 |
Kind Code |
A1 |
Lim; Jaewon ; et
al. |
March 6, 2014 |
METHOD AND DEVICE FOR SELECTING A CHANNEL ACCORDING TO A DEVICE'S
MOBILITY
Abstract
The present invention relates to a method of selecting a
channel, and more particularly, to a method of selecting a channel
according to a Medical Wireless Body Area Network (MBAN) device's
mobility, and of using same. The method includes: receiving, by a
Medical Body Area Network (MBAN) master, a connection request
signal including information on mobility from an MBAN device;
transmitting, by the MBAN master, a connection response signal to
the MBAN device in response to the received connection request
signal; and allocating a channel for the MBAN device according to
the information on mobility in the received connection request
signal.
Inventors: |
Lim; Jaewon; (Gyeonggi-do,
KR) ; Kim; Bonghoe; (Gyeonggi-do, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Lim; Jaewon
Kim; Bonghoe |
Gyeonggi-do
Gyeonggi-do |
|
KR
KR |
|
|
Assignee: |
LG Electronics Inc.
Seoul
KR
|
Family ID: |
47139763 |
Appl. No.: |
14/115666 |
Filed: |
April 5, 2012 |
PCT Filed: |
April 5, 2012 |
PCT NO: |
PCT/KR2012/002590 |
371 Date: |
November 15, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61483076 |
May 6, 2011 |
|
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|
Current U.S.
Class: |
370/331 |
Current CPC
Class: |
H04W 72/048 20130101;
H04W 84/18 20130101; H04W 4/80 20180201 |
Class at
Publication: |
370/331 |
International
Class: |
H04W 4/00 20060101
H04W004/00 |
Claims
1. A method of assigning a channel according to mobility of an MBAN
(medical body area network) device, the method comprising:
receiving, by an MBAN master, an association request signal
including information about the mobility from an MBAN device;
transmitting, by the MBAN master, an MBAN device association
response signal in response to the received association request
signal; and assigning the channel for the MBAN device according to
the information about the mobility included in the received
association request signal.
2. The method of claim 1, wherein the MBAN comprises WPAN (wireless
personal area network).
3. The method of claim 1, wherein the receiving of the association
request signal including the information about the mobility uses a
capability information field.
4. The method of claim 1, wherein in the assigning of the channel
for the MBAN device, the information about the mobility of the MBAN
device comprises at least one selected from the group consisting of
fixed, semi mobile and mobile.
5. The method of claim 1, wherein in the assigning of the channel
for the MBAN device, if the information about the mobility of the
MBAN device is fixed, the MBAN master assigns all of time in which
a primary user does not use a corresponding specific MBAN channel,
or a time longer than that of a mobile MBAN device.
6. The method of claim 5, wherein the MBAN master transmits channel
selection information to the MBAN device by unicast and wherein the
MBAN master operates by a transmission scheme which is not based on
a beacon.
7. The method of claim 1, wherein in the assigning of the channel
for the MBAN device, if the information about the mobility of the
MBAN device is mobile, the MBAN master makes channel selection
information included in a beacon of IEEE 802.15.4 or periodically
transmits a frame including channel selection information to the
MBAN device by unicast.
8. The method of claim 1, wherein in the assigning of the channel
for the MBAN device, if the information about the mobility of the
MBAN device is semi-mobile, channel selection information is
included in a beacon of IEEE 802.15.4 or a frame including channel
selection information is periodically transmitted to the MBAN
device by unicast.
9. The method of claim 1, wherein in the assigning of the channel
for the MBAN device, if the information about the mobility of the
MBAN device is semi-mobile or fixed and channel selection
information is periodically transmitted without a non-beacon based
operation, periodicity of transmitting frame information including
channel selection information is set longer than that of
transmitting the channel selection information to the mobile
device.
10. A method of assigning a channel according to mobility of an
MBAN device, the method comprising: transmitting, by the MBAN
device, an association request signal including information about
the mobility to an MBAN master; receiving, by the MBAN device, an
MBAN device association response signal from the MBAN master in
response to the transmitted association request signal; receiving
information about the channel assigned by the MBAN master according
to the information about the mobility included in the transmitted
association request signal from the MBAN master; and transceiving
data with the MBAN master using the assigned channel.
11. The method of claim 10, wherein the transmitting of the
association request signal including the information about the
mobility uses a capability information field.
12. The method of claim 10, wherein in the receiving of the
assigned channel information from the MBAN master, the information
about the mobility of the MBAN device comprises at least one
selected from the group consisting of fixed, semi mobile and
mobile.
13. The method of claim 10, wherein in the receiving of the
assigned channel from the MBAN master, if the information about the
mobility of the MBAN device is fixed, the MBAN master assigns all
of time in which a primary user does not use a corresponding
specific MBAN channel, or a time longer than that of a mobile MBAN
device.
14. The method of claim 10, wherein in the receiving of the
assigned channel from the MBAN master, if the information about the
mobility of the MBAN device is mobile, channel selection
information is included in a beacon of IEEE 802.15.4 by the MBAN
master, or a frame including channel selection information is
periodically received from the MBAN master by unicast.
15. The method of claim 10, wherein in the receiving of the
assigned channel from the MBAN master, if the information about the
mobility of the MBAN device is semi-mobile, channel selection
information is included in a beacon of IEEE 802.15.4 by the MBAN
master, or a frame including channel selection information is
periodically received from the MBAN master by unicast.
16. The method of claim 10, wherein in the receiving of the
assigned channel from the MBAN master, periodicity of receiving
frame information including channel selection information from the
MBAN master is set longer than that of receiving the channel
selection information by the mobile device.
17. An apparatus for assigning a channel according to mobility of
an MBAN device, comprising: a receiving unit receiving an
association request signal, which is received by an MBAN (medical
body area network) master, including information about the mobility
from the MBAN device; a transmitting unit transmitting an
association response signal from the MBAN master to the MBAN device
in response to the received association request signal; and a
control unit assigning the channel for the MBAN device according to
the information about the mobility included in the received
association request signal.
18. An apparatus for assigning a channel according to mobility of
an MBAN device, comprising: a transmitting unit transmitting an
association request signal including information about the mobility
to an MBAN master from an MBAN device; a receiving unit receiving
an association response signal, which is received by the MBAN
device, from the MBAN master in response to the transmitted
association request signal; a control unit receiving information
about the channel assigned by the MBAN master according to the
information about the mobility included in the transmitted
association request signal from the MBAN master; and a transceiving
unit transceiving data with the MBAN master using the assigned
channel.
Description
TECHNICAL FIELD
[0001] The present invention relates to a channel selection, and
more particularly, to a method of selecting and using a channel in
accordance with mobility of MBAN (medical wireless body area
network) device and apparatus therefor.
BACKGROUND ART
[0002] Owing to the ongoing development of mobile environments, it
becomes unnecessary for a patient to go to the doctor. Instead, a
patient's status is monitored anytime and anywhere and the
monitored information is then forwarded to a hospital by real time
to provide the patient with an appropriate medical service. Thus,
as the appropriate medical services can target ordinary people to
manage user's health anytime and anywhere. This U-health network
industry is rising as a new growth industry and can provide each
individual with sustainably safe life as well as with convenience,
comfortableness, time saving, cost reduction and the like.
[0003] MBAN (medical wireless body area network) can be sorted into
In-body type for monitoring a device implanted in a human body from
an outside of the human body due to in-body propagation property
and On/Out-body short-range communication type for monitoring a
device attached to or provided outside a human body to detect an
effect generated from a human body surface or around a human body
in 3 to 5 meters.
[0004] MICS (medical implant communications system) of the in-body
type provides interactive digital communications between active
medical implant transceivers provided in and out of a human body.
Currently, millions of people live by depending on the active
medical implant devices globally. And, the active medical implant
devices cover a wide scope of medical treatment functions including
heartbeat control, pain control, medication, urinary incontinence
control, diabetic insulin control device, implanted medication
injection device and the like.
[0005] MBAN system is devised to provide a flexible platform for
wireless networking of a multitude of sensors used to monitor
patient's physiological data in health care facility such as a
hospital and the like. The MBAN system operates on
2,360.about.2,400 MHz. Maximum emission bandwidth is limited to 5
MHz. Transmission power amounts to a smaller one of 1 mW and
10*log(B) dBm in case of operation on 2,360.about.2,390 MHz. In
this case, `B` indicates 20-dB emission bandwidth. In case of
operation on 2,390.about.2,400 MHz, a smaller one of 20 mW and
10*log(B) dBm is used as a transmission power. In this case, `B`
indicates 20-dB emission bandwidth.
[0006] 2,360.about.2,400 MHz corresponds to a frequency band
assigned for another wireless communication system in advance. And,
the MBAN system operates on a secondary basis based on cognitive
radio. In particular, harmful interference should not be caused to
a primary user and interference generated form the primary user
should be accepted in use.
[0007] To this end, in case of operation on a band of
2,360.about.2,390 MHz in MBAN, MBAN devices (or terminals) should
basically operate in an indoor space of a registered health care
facility. A use of 2,360.about.2,390 MHz should be controlled
through cooperation with a primary user. When the primary user uses
the corresponding band, all operations on this band should be
initialized and an operation should be resumed using a new band of
2,390.about.2,400 MHz.
[0008] When MBAN devices move outside, they should stop operating
or perform transmissions by changing a transmission band into the
2,390.about.2,400 MHz band used as a basic band. In case of
operating on 2,390.about.2,400 MHz, the MBAN devices are usable
irrespective of an indoor space or an outdoor space. Therefore, in
order to use a channel efficiently, it is necessary to select a
channel according to mobility of an MBAN device.
DISCLOSURE OF THE INVENTION
Technical Task
[0009] Accordingly, one object of the present specification is to
provide a method of selecting a channel and apparatus therefor, by
which efficiency of channel use in MBAN system can be
maximized.
Technical Solution
[0010] To achieve these and other advantages and in accordance with
the purpose of the present invention, as embodied and broadly
described, a method of assigning a channel according to mobility of
an MBAN (medical body area network) device according to one
embodiment of the present invention may include receiving, by an
MBAN master, an association request signal including information
about the mobility from an MBAN device, transmitting, by the MBAN
master, an MBAN device association response signal in response to
the received association request signal, and assigning the channel
for the MBAN device according to the information about the mobility
included in the received association request signal.
[0011] Preferably, the MBAN may include WPAN (wireless personal
area network). And, the receiving of the association request signal
including the information about the mobility may use a capability
information field.
[0012] Preferably, in the assigning of the channel for the MBAN
device, the information about the mobility of the MBAN device may
include at least one of fixed, semi mobile and mobile.
[0013] Preferably, in the assigning of the channel for the MBAN
device, if the information about the mobility of the MBAN device is
fixed, the MBAN master may assign all of time in which a primary
user does not use a corresponding specific MBAN channel, or a time
longer than that of a mobile MBAN device.
[0014] Preferably, in the assigning of the channel for the MBAN
device, if the information about the mobility of the MBAN device is
mobile, the MBAN master may make channel selection information
included in a beacon of IEEE 802.15.4 or periodically a frame
including transmit channel selection information to the MBAN device
by unicast.
[0015] Preferably, in the assigning of the channel for the MBAN
device, if the information about the mobility of the MBAN device is
semi-mobile, channel selection information may be included in a
beacon of IEEE 802.15.4 or a frame including channel selection
information may be periodically transmitted to the MBAN device by
unicast.
[0016] Preferably, in the assigning of the channel for the MBAN
device, periodicity of transmitting frame information including
channel selection information is set longer than that of
transmitting the channel selection information to the mobile
device.
[0017] To further achieve these and other advantages and in
accordance with the purpose of the present invention, a method of
assigning a channel according to mobility of an MBAN device may
include transmitting, by the MBAN device, an association request
signal including information about the mobility to an MBAN master,
receiving, by the MBAN device, an MBAN device association response
signal from the MBAN master in response to the transmitted
association request signal, receiving information about the channel
assigned by the MBAN master according to the information about the
mobility included in the transmitted association request signal
from the MBAN master, and transceiving data with the MBAN master
using the assigned channel.
[0018] Preferably, the transmitting of the association request
signal including the information about the mobility may use a
capability information field.
[0019] Preferably, in the receiving of the assigned channel
information from the MBAN master, the information about the
mobility of the MBAN device may include at least one of fixed, semi
mobile and mobile.
[0020] Preferably, in the receiving of the assigned channel from
the MBAN master, if the information about the mobility of the MBAN
device is fixed, the MBAN master may assign all of time in which a
primary user does not use a corresponding specific MBAN channel, or
a time longer than that of a mobile MBAN device.
[0021] Preferably, in the receiving of the assigned channel from
the MBAN master, if the information about the mobility of the MBAN
device is mobile, channel selection information may be included in
a beacon of IEEE 802.15.4 or a frame including channel selection
information may be periodically received from the MBAN master by
unicast.
[0022] Preferably, in the receiving of the assigned channel from
the MBAN master, if the information about the mobility of the MBAN
device is semi-mobile, channel selection information may be
included in a beacon of IEEE 802.15.4 by the MBAN master or a frame
including channel selection information may be periodically
received from the MBAN master by unicast.
[0023] Preferably, in the receiving of the assigned channel from
the MBAN master, periodicity of receiving frame information
including channel selection information from the MBAN master may be
set longer than that of receiving the channel selection information
by the mobile device.
Advantageous Effects
[0024] In a method of selecting a channel in accordance with
mobility of an MBAN device in an MBAN system according to one
embodiment disclosed in this specification, as mentioned in the
foregoing description, communications can be performed while
maximizing efficiency in using the channel for the MBAN device.
DESCRIPTION OF DRAWINGS
[0025] FIG. 1 shows a frame structure of IEEE 802.15.4 according to
a related art disclosed in this specification.
[0026] FIG. 2 shows a format of a beacon frame of IEEE 802.15.4
according to a related art disclosed in this specification.
[0027] FIG. 3 shows a frame format of an association request
command of IEEE 802.15.4 according to a related art disclosed in
this specification.
[0028] FIG. 4 shows a frame format of a capability information
field of IEEE 802.15.4 according to a related art disclosed in this
specification.
[0029] FIG. 5 is a block diagram of a connected structure of
primary components of MBAN and contents of transmitted information
according to one embodiment disclosed in this specification.
[0030] FIG. 6 is a signaling flowchart of a process for selecting a
channel between an MBAN master and an MBAN device according to
mobility of the MBAN device according to one embodiment disclosed
in this specification.
[0031] FIG. 7 shows attributes of an MBAN device to illustrate
mobility of the MBAN device according to one embodiment disclosed
in this specification.
[0032] FIG. 8 shows one example of applying a mobility attribute
for mobility of an MBAN device according to one embodiment
disclosed in this specification to a capability information field
of the existing IEEE 802.15.4.
BEST MODE FOR INVENTION
[0033] First of all, various modifications and variations can be
made in the present invention without departing from the spirit and
scope of the invention. Reference will now be made in detail to the
preferred embodiments of the present invention, examples of which
are illustrated in the accompanying drawings. Thus, it is intended
that the present invention covers the modifications and variations
of this invention that come within the scope of the appended claims
and their equivalents, instead of limiting the present invention to
a specific embodiment.
[0034] A terminology including an ordinal number as 1.sup.st,
2.sup.nd and the like used in this specification may be usable to
describe various components. Yet, each of the components should be
non-limited by the terminology including the ordinal number. The
terminology including the ordinal number is used only to
discriminate one component from another. For instance, a 1.sup.st
component may be named a 2.sup.nd component without departing from
the scope of the appended claims and their equivalents. Similarly,
a 2.sup.nd component may be named a 1.sup.st component for example.
A terminology `and/or` may include a combination of a plurality of
related and disclosed items or a prescribed one of a plurality of
the related and disclosed items.
[0035] When a prescribed component is mentioned as `connected to`
or `accessed by` a different component, it may be directly
connected to or accessed by the different component. Yet, another
different component may exist in-between. On the contrary, when a
prescribed component is mentioned as `directly connected to` or
`directly accessed by` a different component, it is understood that
another different component does not exist in-between.
[0036] Terminologies used in the present application are used to
describe a specific embodiment only, by which the present invention
may be non-limited. A singular representation used in this
specification may include a plural representation unless apparently
different in the context of usage. In the present application, such
a terminology as `include`, `have` and the like is intended to just
designate the presence of features, numerals, steps, operations,
components, parts and combinations thereof, which are disclosed in
a specification, and should be understood as not excluding the
presence or addition possibility of at least one or more features,
numerals, steps, operations, components, parts and combinations
thereof in advance.
[0037] Unless defined different, all terminologies, used herein,
including technical and/or scientific terminologies have the
meanings generally understood by those skilled in the art to which
the present invention pertains. Moreover, a general terminology
used by the present invention should be construed as the definition
in dictionary or in accordance with the context and should not be
construed as an excessively reduced meaning.
[0038] Reference will now be made in detail to the preferred
embodiments of the present invention, examples of which are
illustrated in the accompanying drawings. In the following detailed
description of the invention includes details to help the full
understanding of the present invention. Wherever possible, the same
reference numbers will be used throughout the drawings to refer to
the same or like parts and redundant description shall be
omitted.
[0039] FIG. 1 shows a frame structure of IEEE 802.15.4 according to
a related art disclosed in this specification.
[0040] In IEEE 802.15.4 LR-WPAN (low power-wireless personal area
networks), a coordinator periodically broadcasts a beacon frame to
a device inside a network or a network device. According to the
standard, an interval between a beacon frame and a beacon frame is
defined as a super frame. The super frame carries data by being
divided into CAP (contention access period) and CFP (contention
free period).
[0041] The super frame starts with a beacon of a coordinator of a
PAN (personal area network) coordinator and a BI (beacon interval)
is divided into an active interval and an inactive interval. A
beacon frame does not carry a beacon if a use of each super frame
is not wanted. Yet, in case of using a beacon frame, a beacon is
used to synchronize devices, identify a PAN, and describe a super
frame structure.
[0042] The active interval (i.e., Superframe Duration (SD)) is
divided into 16 superframe slots in equal size and is configured
with CAP operating as slotted CSMA/CA (carrier sense multiple
access/collision detect) and CFP operating as GTS (guaranteed time
slot). During the inactive interval (i.e., Beacon Interval (BI)),
the coordinator can enter a low-power mode.
[0043] The BI and SD shown in FIG. 1 can be configured by setting
BO (beacon order) and SO (superframe order) of PIB (PAN information
base). LT-WPAN uses two kinds of channel access mechanisms (i.e., a
beacon non-use PAN and a beacon use PAN) for a configuration of a
network. In this case, the beacon use PAN uses a slotted CSMA/CSA
channel access mechanism.
[0044] A device having transmission data randomly selects a value
of backoff or delay time in a range [0, 2.sup.BE-1]. In this case,
the BE is an exponent for the backoff and its value indicates a
range for the backoff selection. In case of attempting to transmit
a frame in CAP (contention access period), each device stands by
for a randomly selected slot. If a channel is in busy state, the
corresponding device selects another random backoff value and then
stands by for the selected value. If a channel is in idle state, a
device attempting a transmission can perform the transmission on a
next backoff slot boundary.
[0045] CSM/CA algorithm is used before a transmission of data or
MAC command frame transmitted in CAP. Otherwise, the frame is
transmitted right after ACK of a data request command. In the
beacon use PAN, the CSM/CA algorithm is not used for a transmission
of a beacon frame, a transmission of ACK frame or data frame
transmitted in CFP.
[0046] FIG. 2 shows a format of a beacon frame of IEEE 802.15.4
according to a related art disclosed in this specification.
[0047] In a beacon interval, a coordinator broadcasts a beacon
frame including various kinds of network parameters such as
synchronization information and the like to the rest of devices. In
CAP, each device transmits such a frame as an access request and
the like. In doing so, a channel access for the frame transmission
is performed through contention between devices.
[0048] In CFP configured with a multitude of guaranteed time slots
(GTSs), a specific device transmits a data frame and the like in
GTS assigned by a coordinator device without contention with other
devices. In an idle period, all devices including the coordinator
device enter a power save mode and frame transmissions are not
performed between the coordinator device and other devices.
[0049] Thus, according to IEEE 802.15.3 specifications or IEEE
802.15.4 specifications, in order to receive a beacon frame from a
coordinator device, a receiving end (Rx) of each device should be
awake in a beacon interval of a superframe at least. In particular,
each device should be awake in each superframe interval, i.e., each
beacon interval once at least. This is to share overall information
of a network through a beacon frame as well as information about a
superframe.
[0050] Referring to FIG. 2, a format of a beacon frame can include
a format of MHR (MAC header) including a frame control field, a
sequence number field, a source address field, an auxiliary
security header and the like.
[0051] Moreover, the format of a beacon frame can further include a
format of MAC payload including a superframe specification field, a
GTS (guaranteed time slot) field, a pending address field, a beacon
payload and the like and a format of MFR (MAC footer) including FCS
(frame check sequence).
[0052] FIG. 3 shows a frame format of an association request
command of IEEE 802.15.4 according to a related art disclosed in
this specification.
[0053] In order for a node to join WPAN, a node registration
procedure by a manager is necessary. To this end, an authentication
certificate issued by a reliable authentication organization of a
third party is used. Assume that every node is provided by a
manufacturer with a unique identifier, information of a device and
a pair of a secret key and a public key and then authenticated by
the reliable authentication organization of the third party. A PAN
coordinator receives such information from a node to be joined,
performs validation, and is then able to determine whether to
register the node actually according to a selection made by the
manager.
[0054] After a beacon signal has been transceived between the node
and the PAN coordinator, the node make a request for association to
the PAN by sending an association request command and the
authentication certificate of the node. The authentication
certificate of the node includes an identifier of the node, a
public key of the node, a data code containing node information, a
signature of the authentication organization and the like and is
transmitted together with a signature of a device. Having received
them, the PAN coordinator can validate the authentication
certificate and the signature using the public key of the device
obtained from the authentication certificate.
[0055] After completion of the validation of the authentication
certificate and signature, the manager checks the information of
the device of the node and then determines whether to register the
node. If the manager determines the registration of the node, the
PAN coordinator transmits an association response command to
approve the join of the node and saves the authentication
certificate and signature of the node.
[0056] Meanwhile, an association request command can request a
device to be connected to a PAN through a PAN coordinator or a
coordinator. This command can be transmitted by a device not
connected to the PAN currently only. The device can be connected to
the PAN only through the PAN coordinator or a coordinator allowed
to be connected by being determined through a scan procedure.
Although an RFD (reduced function device) is not requested to
receive an association request command, every device can transmit
an association request command.
[0057] Referring to FIG. 3, the association request command can be
represented in a format including an MHR (MAC header) including a
frame control field, a sequence number field, a source address
field, an auxiliary security header and the like, a command frame
identifier, and capability information.
[0058] FIG. 4 shows a frame format of a capability information
field of IEEE 802.15.4 according to a related art disclosed in this
specification.
[0059] Referring to FIG. 4, the capability information field
mentioned in the foregoing description with reference to FIG. 3 may
further include a PAN coordinator selection (alternate PAN
coordinator) subfield, a device type subfield, a power source
subfield, a receiver on when idle subfield, a reserved subfield, a
security capability subfield, an allocate address subfield and the
like.
[0060] The alternate PAN coordinator subfield has 1-bit length. If
a device can become a PAN coordinator, this subfield is set to 1.
Otherwise, this subfield is set to 0 (zero). The device type
subfield has 1-bit length. If a device is configured as FDD
(full-function device), this subfield is set to 1. Otherwise, i.e.,
if this field indicates an RFD (reduced function device), it is set
to zero.
[0061] The power source subfield has 1-bit length. If a device is
receiving a power not from a main power source but from another
place, this subfield is set to 1. Otherwise, this subfield is set
to zero. The receiver on when idle subfield is set to 1 if a
reliever power of a device is not disabled to reserve a power from
a receiver during an idle period. Otherwise, this subfield is set
to zero.
[0062] The security capability subfield has 1-bit length. If a
device is able to transmit or receive a protected MAC frame
cryptographically, this subfield is set to 1. Otherwise, this
subfield is set to zero. The allocate address subfield has 1-bit
length. If a device wants a coordinator to allocate a short 16-bit
address as a result of an association procedure, this subfield is
set to 1. Otherwise, this subfield is set to zero.
[0063] FIG. 5 is a block diagram of a connected structure of
primary components of MBAN and contents of transmitted information
according to one embodiment disclosed in this specification.
[0064] FIG. 5 shows a connected structure of primary components of
MBAN and contents of transmitted information. In particular, if an
MBAN coordinator 510, which manages a database (DB) including
information indicating when channels on 2,360.about.2,390 MHz band
are effective, delivers the corresponding information to an MBAN
control point 520 through an electronic key, the MBAN control point
delivers an authorized MBAN frequency information to an MBAN master
530 through a beacon information.
[0065] The MBAN master 530 schedules a frequency, which is to be
assigned to a device, based on the authorized MBAN frequency
information delivered to the MBAN master 530 and then delivers it
to an MBAN slave device 540 through a frequency selection
information, thereby enabling the MBAN slave device 540 to
communicate with the MBAN master 530 through an MBAN channel
designated to the MBAN slave device 540.
[0066] In the following description, an MBAN slave device (slayer)
shall be named an MBAN device (or terminal).
[0067] FIG. 6 is a signaling flowchart of a process for selecting a
channel between an MBAN master and an MBAN device according to
mobility of the MBAN device according to one embodiment disclosed
in this specification.
[0068] Referring to FIG. 6, a method of selecting a channel between
an MBAN master and an MBAN device (or terminal) in accordance with
mobility of the MBAN device includes a step S1 for an MBAN to
perform an association request, a step S2 for an MBAN master 20 to
perform an association response in response to the association
request, steps S3 and S4 for the MBAN master to select a channel
between the MBAN master and the MBAN device (or terminal) in
accordance with mobility of the MBAN device, and a step S5 of
transmitting data on the selected channel.
[0069] In the following description, a process for a representative
CM to allocate a resource in central type topology is explained in
detail with reference to FIG. 6.
[0070] FIG. 6 shows a process for selecting a channel selection
method between an MBAN master 20 and an MBAN device 10 according to
mobility of the MBAN device proposed in this specification. In an
association step, the MBAN device 20 transmits an association
request frame including information indicating its mobility to the
MBAN master 20 [S1].
[0071] A value of the mobility of the MBAN device 10 may have one
of three kinds of values `fixed`, `semi-mobile` and `mobile`. The
MBAN device having the fixed value is installed on a place and then
used by being fixed to the corresponding place. The MBAN device
having the mobile value is an MBAN device having frequency
mobility. And, the semi-mobile MBAN device is mobile but has a
mobility frequency lower than that of the mobile MBAN device.
[0072] Having received the association request frame from the MBAN
device 10, the MBAN master 20 transmits an association response
frame to the MBAN terminal [S2].
[0073] Subsequently, if the mobility of the MBAN device (or
terminal) 10 is `fixed`, since the corresponding MBAN device has no
mobility and is communicating with the MBAN master only at a
currently located place, the MBAN master 20 is able to assign all
of time in which a primary user does not use a corresponding
specific MBAN channel, or a time relatively longer than that of a
mobile MBAN terminal to the MBAN terminal.
[0074] In this case, the MBAN master 20 can deliver channel
selection information to the MBAN terminal using a unicast frame
transmitted to a specific recipient like the case of Option 1 shown
in FIG. 6 [S3]. Moreover, if it is expected that the MBAN master 20
will communicate with a fixed MBAN device only, the MBAN master 20
operates by the non-beacon scheme of IEEE 802.15.4, thereby
reducing system overhead due to a transmission of a beacon
frame.
[0075] In case that the mobility of the MBAN device (or terminal 10
is `mobile`, the MBAN master 20 periodically transmits channel
assignment information to the MBAN terminal and checks whether the
corresponding MBAN terminal is located within a transmission range
of the MBAN master 20. In doing so, the MBAN terminal periodically
checks the channel assignment information transmitted from the MBAN
master and checks whether the MBAN terminal currently receives a
service from the same MBAN master.
[0076] If the MBAN terminal 10 confirms that it enters a
transmission range of a new MBAN master, the MBAN terminal 10 needs
to access the new MBAN master by performing the association
procedure again. In case of expecting an access of a mobile MBAN
device, the MBAN master makes channel selection information
included in a beacon of IEEE 802.15.4 (Option 2) [S4] or can
periodically transmit a frame including channel selection
information to the MBAN device by unicast (Option 1) [S3].
[0077] If the mobility of the MBAN terminal (or device) 10 is
`semi-mobile`, the MBAN master makes channel selection information
included in a beacon of IEEE 802.15.4 (Option 2) [S4] or
periodically transmits a frame including channel selection
information to the MBAN device by unicast. In doing so, the
periodicity for transmitting the channel selection information
included information may be set longer than that for transmitting
the channel selection information to the mobile terminal.
[0078] In the following description, a mobility parameter of a
specific MBAN device is defined and a protocol and frame structure
for delivering the mobility parameter are proposed.
[0079] FIG. 7 shows attributes of an MBAN device to illustrate
mobility of the MBAN device according to one embodiment disclosed
in this specification.
[0080] FIG. 7 shows mobility attribute of an MBAN device to
indicate terminal mobility proposed by the present specification.
The attribute for MBAN mobility (i.e., mobility attribute) is
represented as a 2-bit value. If a bit value indicating a binary
value is 00, it indicates `fixed`. If the bit value is 01, it
indicates `semi-mobile`. If the bit value is 10, it indicates
`mobile`. If the bit value is 11, it is reserved for the extension
in the future.
[0081] FIG. 8 shows one example of applying a mobility attribute
for mobility of an MBAN device according to one embodiment
disclosed in this specification to a capability information field
of the existing IEEE 802.15.4.
[0082] Referring to FIG. 8, a capability information field shown in
FIG. 8 plays a role in informing an MBAN master of capability of a
device by being included in an association request transmitted to
the MBAN master by an MBAN device (or terminal). In this case,
shown is one example of applying mobility attribute proposed by the
present specification using 4.sup.th and 5.sup.th bits of a
reserved field of the existing capability information field of IEEE
802.15.4.
[0083] The terminal described so far can be generally named a
device and includes every terminal capable of implementing the
embodiments shown in FIGS. 2 to 8. In particular, a terminal
according to the present invention, i.e., a device inclusively
includes one of a mobile communication terminal (e.g., a user
equipment (UE), a cellular phone, a DMB phone, a DVB-H phone, a PDA
phone, a PTT phone, etc.) capable of implementing the
above-described technical idea of the present invention, a digital
TV, a GPS navigation system, a portable game player, an MP3, other
home appliances and the like.
[0084] Moreover, a terminal according to the present invention
includes software for implementing the embodiments shown in FIGS. 1
to 8 or a module on which the software is installed. This module is
one component of the terminal and may be named a processor or
controller. A terminal according to the present invention includes
mandatory hardware and software components necessary for
implementing the above-described technical features of the present
invention.
[0085] The above-described method according to the present
invention may be implemented by software, hardware or combination
of software and hardware. For instance, a method according to the
present invention may be saved in a storage medium (e.g., an
internal memory, a flash memory, a hard disk, etc.) and may be
implemented with codes or commands in a software program executable
by a processor (e.g., a microprocessor, etc.).
[0086] So far, apparatus and method according to at least one
embodiment disclosed in the present specification are described
with reference to the accompanying drawings, by which the present
specification may be non-limited. And, it is a matter of course
that various modifications can be performed by those skilled in the
art, to which the present invention pertains, within the scope of
the technical idea of the present invention.
[0087] Regarding the above-described channel selecting method
according to mobility of an MBAN device, configurations and methods
of the above-described embodiments are not limitedly applicable but
the embodiments can be configured in a manner of being selectively
combined entirely or in part to enable various modifications of the
embodiments.
[0088] So far, the embodiments disclosed in the present
specification are described with reference to the accompanying
drawings.
[0089] In this case, terminologies or vocabularies used in the
present specification and the claims should be construed as the
meanings and concepts matching the technical idea disclosed in the
present specification instead of being limited to the general or
dictionary definition.
[0090] While the present invention has been described and
illustrated herein with reference to the preferred embodiments
thereof, it will be apparent to those skilled in the art that
various modifications and variations can be made therein without
departing from the spirit and scope of the invention. Thus, it is
intended that the present invention covers the modifications and
variations of this invention that come within the scope of the
appended claims and their equivalents.
* * * * *